Dziani Boundouni, Volcanic lake in Mohéli, Comoros.

Dziani Boundouni is a volcanic crater lake in southeastern Mohéli, about 400 m long and 200 m wide, with brackish, sulfurous water. Its crater rims rise steeply to 160 m on the inland north side and 120 m on the seaward south side. A path from Hamavouna on the west coast leads around the northern rim to Itsamia on the east coast.

Dziani Boundouni was listed as a Ramsar wetland on 9 February 1995, within the Mohéli marine park, which covers about 30 hectares around the lake. The listing gave formal protection to the lake, its surrounding forest and its waterbird populations. Limnological readings and upwellings of water have been read as signs of underground volcanic activity, and underground links to the ocean may exist.

The lake lies within Mohéli Marine Park and has been a Ramsar wetland since 9 February 1995. Local people and visitors come to watch birds such as the 446 little grebes and 600 Madagascar pond herons recorded there, and to see the surrounding forest with its Comorian endemic trees.

Early morning visits offer the best conditions for birdwatching, as most species are most active at that time. Sturdy footwear and insect repellent are advisable due to the wet and marshy terrain around the shoreline.

The lake's water displays unusual chemical properties suggesting possible underground connections to the ocean. These features indicate ongoing volcanic activity beneath the surface that shapes the ecosystem in unexpected ways.